“BPA-free” is as deceptive as “0 grams of trans fat”

You know how the food companies are allowed to advertise their products as having “0 grams of trans fat” as long as the amount of trans fat per serving is less than 0.5 grams. (If a food product has hydrogenated or partially-hydrogenated oils of any type, it has trans fat.) So my question is are the “BPA-free” plastic bottles seen in the stores TRULY “BPA-free”, or are they allowed to advertise their products as “BPA-free” as long as the BPA content of the entire plastic volume is less than 1% or 0.5%?